What we know to be a copy by common sense, real world interpretation of the word "copy" is not necessarily what copyright law considers to be a "copy" for the p

What we know to be a copy by common sense, real world interpretation of the word "copy" is not necessarily what copyright law considers to be a "copy" for the purposes of enforcing copyright laws. Is holding a book up to a half-silvered mirror making a copy of it? Is looking over someone else's shoulder as they read making a copy? Do the activation levels in a person's visual cortex count as a copy? It may be useful to keep hairs unsplit, forget about the quantum mechanics of copying and focus on the observers. If there are two files with identical content on a filesystem such that only one user is authorized to read them, how many copies exist? To me, that's two copies in fact, but one copy by copyright law, in that the second real-life copy is not separable from the first for the purposes of commerce. The act of changing the access permissions on the second identical file would be what makes it a copyright-copy, not the act of duplicating the bits.